1. Field of the Invention
This invention relates to a method of preparing polysubstituted acylbenzenes and more particularly to synthesizing these acylbenzenes by means of a perfluoro sulfonic acid polymer acylating catalyst.
2. Discussion of the Prior Art
When an acyl halide or equivalent is reacted with 2-bromo-1, 3-dimethoxybenzene to form the corresponding acylbenzene it has been found that rearrangement products either predominate or at least are present as major contaminants when usual acylating or Friedel-Crafts catalysts are employed. Such rearrangement products involve bromine migration from the 2 to 4 position, e.g., ##STR1## As resported by G. A. Olah, et al., in Synthesis, 1978 672, a solid perfluorinated resin sulfonic acid, commercially available from E. I. DuPont de Nemours as Nafion H, can be employed as an acylating catalyst in reactions between acyl halides, anhydrides, or mixtures of acids and their anhydrides and other substituted benzenes. However, it has not heretofore been reported or suggested that such a perfluorinated resin sulfonic acid could function to prevent the formation of rearrangement products when 2-bromo-1,3-dimethoxybenzene is employed.